JP2000296470A - Internal grinding wheel and circular workpiece grinding device using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To grind inner and outer diameter surfaces of even workpieces, such as glass workpieces, which are liable to chip or crack, efficiently, precisely and inexpensively. SOLUTION: An internal grinding wheel 4 with grinding grooves in the internal surface is positioned on a wheel spindle support cylinder 5, in which a cylindrical wheel spindle 6 is passed vertically and journalled so as to fixedly support the internal grinding wheel 4 on the top surface, and in which means are provided to rotate the wheel spindle 6. The wheel spindle 6 receives a loosely inserted workpiece spindle support cylinder 18 having on its upper end a lower workpiece clamp 20 for attracting a workpiece 12. The wheel spindle support cylinder 5 and/or the workpiece spindle support cylinder 18 is movable in the vertical and horizontal directions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention mainly relates to glass,
Donuts of ceramic, silicon, etc., and other circular wires
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner peripheral grindstone for efficiently performing peripheral surface grinding and chamfering of an outer diameter and an inner diameter of a work and a grinding apparatus for a circular work using the same.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for circular works such as silicon wafers for manufacturing LSIs and the like and glass hard disk substrates for computers.
There is an increasing demand for grinding the outer and inner diameters of such a work efficiently and at low cost.

[0003] The outer diameter or inner / outer diameter processing of this kind of work is generally performed by an outer peripheral grindstone 45 having an outer peripheral surface bonded with abrasive grains. In this case, the contact portion between the grindstone and the work is small.
Since it is point grinding, it takes a long time to grind and has a drawback that the load is concentrated on the work (see FIG. 7).
If the depth of cut is increased in order to increase the grinding efficiency, chips and cracks are more likely to occur in the case of a work such as glass, and the machining surface is likely to be defective. Therefore, it is not possible to increase the depth of cut to increase the grinding efficiency. Also, for the same reason,
The rotation speed of the shaft cannot be increased.

[0004]

As described above, the conventional circular work grinding apparatus has a poor grinding efficiency and cannot meet the demand for cost reduction. Therefore, the present invention meets such a demand. In other words, even if the workpiece is susceptible to chipping or cracking, such as a glass workpiece, an inner grinding wheel capable of performing the inner and outer diameter grinding efficiently, accurately and at low cost. An object of the present invention is to provide a grinding device for a circular work using the same.

[0005]

According to the present invention, there is provided an inner peripheral grindstone comprising a plurality of stages of trapezoidal grinding grooves having abrasive grains such as diamond fixed on the inner peripheral surface of a donut-shaped main body. Solved the problem. A flat grinding peripheral surface may be formed together with the plurality of grinding grooves, and preferably, in the plurality of grinding grooves, the type and / or the grain size of the abrasive grains are different.

The present invention also provides a grindstone shaft support cylinder on which an inner grindstone having a grinding groove formed on the inner peripheral surface is provided, and the grindstone shaft support cylinder penetrates in the up-down direction and the upper surface thereof has A means for rotatably supporting a cylindrical grindstone shaft for fixing the shaft is provided, and a lower work clamp for adsorbing a work is provided at the upper end of the grindstone shaft. A grinding device for a circular work, wherein the work shaft support cylinder is inserted in a loosely inserted state and the whetstone shaft support cylinder and / or the work shaft support cylinder can be moved vertically and horizontally. The above problem has been solved.

[0007]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIGS. 1 and 2 show the configuration of a grinding apparatus according to the present invention. In the drawings, reference numeral 1 denotes a support bracket, which has a rail 2 extending in the vertical direction on a side surface thereof, and an upper portion of which is provided with the present invention described later. A servo motor 3 for positioning the inner peripheral grinding wheel 4 in the vertical direction is provided. Reference numeral 5 denotes a shaft support cylinder for supporting the cylindrical grindstone shaft 6 of the grindstone 4, and one or a plurality of LM balls which are locked to the rail 2 on its side surface and move up and down along the rail 2. 7 is installed.
The LM ball 7 is provided with a ball screw nut 7a which meshes with a ball screw fixed to the rotating shaft of the servo motor 3, and thereby supports the shaft with the operation of the servo motor 3. Cylinder 5
Moves up and down, thereby positioning the inner peripheral grinding wheel 4 in the up-down direction.

Reference numeral 8 denotes a motor for rotating a grindstone mounted on the upper surface of the shaft support cylinder 5, and a starting pulley 9 is fixed to a rotating shaft end protruding from the lower surface of the shaft support cylinder 5. A driven pulley 10 corresponding to the starting pulley 9 is provided at the lower end of the grinding wheel shaft 6.
Is fixed, and the belt 11 is looped between the pulleys 9 and 10. Therefore, with the operation of the grinding wheel rotating motor 8,
The inner peripheral grindstone 4 fixed to the upper surface of the grindstone shaft 6 rotates.

The inner peripheral grindstone 4 is different from a general outer peripheral grindstone in which abrasive grains are fixed on the outer peripheral face, and abrasive grains such as diamond are electroplated or bonded to the inner peripheral face of a donut-shaped main body. A variety of embodiments are conceivable, which are fixed using an agent. Usually, abrasive grains are fixed on the entire flat peripheral surface. However, thin wafers such as glass hard disks and silicon wafers, which are mainly processed in the apparatus according to the present invention, are considered. As shown in FIG. 3, it is conceivable to process the −k 12. This is provided with a large number of grinding grooves 13 for simultaneously performing the outer peripheral processing and the chamfering processing of the work 12.
3 has a groove bottom 14 for performing the outer peripheral processing and inclined surfaces 15 and 16 for performing the chamfering processing (FIG. 4). As is clear from the figure, the chamfer angle is determined by the angle α of the inclined surfaces 15 and 16.

In the case of the inner peripheral grinding wheel 4, there are many contact portions with the work 12, so that the load on the work 12 is dispersed since the surface is ground in a so-called contact state (FIG. 6). The work 12 is unlikely to be chipped or cracked.

Next, this point will be described in more detail. According to a trial calculation, 0.6 mm of a piece of meat of a work 12 having a diameter of 65 mm is calculated as follows.
Work 1 when processing with a 160 mm diameter outer peripheral grindstone 45
The contact length between 2 and the outer peripheral grindstone is 10.307 mm, and the cutting amount when plunge cutting it is 3.9116 mm2. On the other hand, when a work 12 of the same size is machined with an inner peripheral grindstone 4 having an inner diameter of 105 mm, the contact length is 19.919 mm and the cutting amount is 7.
6385mm, which is about twice as large. When a work 12 of the same size is machined with an inner peripheral grindstone 4 having an inner diameter of 72 mm, the contact length is 40.031 mm and the cutting amount is 15.3159 mm2.
And both are approximately four times the numerical value.

As described above, there is a remarkable difference in the length of contact with the work 12 and the amount of cutting between the case of the outer peripheral grindstone 45 and the case of the inner peripheral grindstone 4. However, it can be easily understood that the load applied to the work 12 is dispersed, so that even a material such as glass is unlikely to cause chipping or cracking during processing. In addition, since the contact area of the grindstone is difficult to reach the outer peripheral surface of the processing due to the large contact area, and since the concentrated load is small, there is an advantage that the cutting size can be increased and the processing efficiency can be significantly improved.

As another mode, the inner peripheral grinding wheel 4 shown in FIG. 5 has a grinding groove 13 similar to that described above in the lower half and a flat peripheral surface 17 in the upper half. In any case, by changing the type and grain size of the abrasive grains in each of the grinding grooves 13, it is possible to selectively use the abrasive grains for roughing and finishing.

A work shaft support cylinder 18 is inserted into the grindstone shaft 6 with a sufficient margin in the lateral direction. Shaft support cylinder 18
Is fixed on the horizontal plate 19a of the box unit 19, as shown in FIG. In the work shaft support cylinder 18,
A lower work clamp 20 is fixed to an upper end, and a work shaft 22 to which a driven gear 21 is fixed is inserted and supported by a lower end.

Reference numeral 24 denotes a bracket 2 below the horizontal plate 19a.
The drive gear 24a meshed with the driven gear 21 is fixed by a work rotating motor mounted via the rotary shaft 5 via the rotating shaft. Therefore, when the work rotating motor 24 operates, the work shaft 2 is driven via the drive gear 24a and the driven gear 21.
2 is driven to rotate, whereby the work 12 sucked by the lower work clamp 20 rotates.

Although not shown, the inside of the work shaft 22 is an air bleeding passage communicating with the air bleeding hole in the lower work clamp 20, and a rotary joint 26 is provided at the lower end thereof.
The work 12 is sucked through these vacuum pipes, the rotary joint 26, the air vent passage, and the air vent hole.

When the diameter of the work 12 is large, the suction area can be increased, so that the work 12 can be sucked only by the lower work clamp 20, but when the diameter of the work 12 is small. Is provided with an upper work clamp 27 which presses the work 12 from above and securely holds the work 12 between the work clamp 12 and the lower work clamp 20.

The upper work clamp 27 is rotatably supported by a clamp support plate 28 which moves up and down. The upper ends of the guide shafts 29, 29 are fixed to both ends of the clamp support plate 28, and the lower ends of the guide shafts 29, 29 are connected by a connecting plate 30. Guide shaft 29, 29
Are slidably inserted into and supported by ball bush guides 31, 31 installed at both ends of the horizontal plate 19 a in a vertical direction.

Reference numeral 32 denotes one or two lifting cylinders installed on the back side of the horizontal plate 19a, and the rods thereof are fixed to the connecting plate 30. Therefore, when the lifting cylinder 32 operates,
The operation is transmitted to the upper work clamp 27 via the connecting plate 30, the guide shaft 29, and the clamp support plate 28, so that the upper work clamp 27 moves up and down.

The support bracket 1 has a ball screw nut 4
2, a ball screw 44 driven by a servo motor 43 mounted on a column (not shown) is screwed therein. Thus, with the operation of the servo motor 43, each part attached to the support bracket 1 moves in the horizontal direction, and the cutting position of the inner peripheral grinding wheel 4 is determined.

For a circular work such as a silicon wafer for which only outer diameter grinding is performed, the support bracket 1 is fixed and the work side is moved by the same means as described above to position the cut. It may be that.

The above configuration is sufficient for grinding the outer diameter of the work. However, when the inner and outer diameters are ground as in a donut type work, the following configuration is further added. .
That is, 33 is a grindstone for machining the inside diameter of the work 12, and
It travels through the grindstone insertion hole 34 formed at the center of the ukulamp 27 and into the escape hole 35 of the lower work clamp 20. Reference numeral 36 denotes a shaft support cylinder for supporting the grindstone shaft of the grindstone 33 for the inside diameter machining.
7 is attached to this.

A ball screw nut 39 is fixed to the shaft support cylinder 36, and a ball screw 41 driven by a servo motor 40 mounted on a column (not shown) is screwed into the ball screw nut 39. Accordingly, when the servo motor 40 is operated, the shaft support cylinder 36 and the grindstone 33 for inner diameter processing are moved horizontally via the ball screw 41 and the ball screw nut 39, and the cutting position is determined. Similarly, by installing a servo motor for vertical movement, a ball screw and a ball screw nut, the shaft support cylinder 36 and the grindstone 33 for machining the inside diameter are moved in the vertical direction, and the vertical positioning is performed. Is made.

The operation of the illustrated example of the above construction will now be described. First, as shown in FIG. 2, the lower work clamp 20 is manually or mechanically moved in a positional relationship away from the inner grinding wheel 4. -Work 12 with lower work clamp 20
Place on top and allow to adsorb. Next, the cylinder 32 is operated to lower the upper work clamp 27, and the work 12 is clamped from both the upper and lower sides to start grinding. The grinding may be performed from the inner diameter of the work 12, from the outer diameter, or simultaneously from the inner and outer diameters.

The inner diameter grinding of the workpiece 12 is performed by rotating the work 12 and operating the inner diameter processing motor 37 to rotate the inner diameter processing grindstone 33, and then operating the servo motor 40. Then, the cutting position of the grinding wheel 33 for inner diameter processing is determined. The selection of the grinding groove 13 of the inner diameter grinding wheel 33 is performed by operating a servo motor (not shown) in advance or while the work 12 and the inner peripheral grinding wheel 4 are rotating.

In the outer diameter grinding of the work 12, the work 12 is rotated and the grindstone rotating motor 8 is operated to rotate the inner grindstone 4, and then the servo motor is used. By operating 43, the cutting position of the inner peripheral grinding stone 4 is determined. In addition, before or during rotation of the work 12 and the inner peripheral grinding wheel 4, the servomotor
The grinding groove 13 is selected by operating the shaft 3 and moving the shaft support cylinder 5 up and down.

When grinding the inner and outer diameters, the cutting efficiency of the inner and outer diameters is determined at the same time, whereby the grinding efficiency can be improved.

Although the above description relates to a donut-shaped circular work or a plate-shaped circular work, the apparatus according to the present invention is applicable to other works, for example, a cylindrical or square work.
Needless to say, it is also possible to use the network.

[0029]

The present invention is as described above. Since the inner peripheral grindstone is used for the outer peripheral processing of the work, the grinding efficiency can be increased without overworking the work and the processing cost can be reduced. The cost can be reduced, and at this time, there is an effect that the yield is improved because the work is hardly chipped or cracked. Further, the processing accuracy and surface roughness are remarkably improved as compared with the case of the outer peripheral whetstone processing. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view of a grinding device according to the present invention.

FIG. 2 is a partially omitted side view of the grinding apparatus according to the present invention.

FIG. 3 is a longitudinal sectional view showing an example of the shape of an inner grinding wheel according to the present invention.

FIG. 4 is a view showing a grinding groove of an inner peripheral grinding wheel according to the present invention.

FIG. 5 is a longitudinal sectional view showing another example of the shape of the inner peripheral grinding wheel according to the present invention.

FIG. 6 is a view showing a state of grinding with an inner peripheral grinding wheel according to the present invention.

FIG. 7 is a view showing a state of grinding using a conventional outer peripheral grindstone.

[Explanation of symbols]

 4 Inner peripheral grindstone 5 Grindstone shaft support cylinder 6 Cylindrical grindstone shaft 12 Work 18 Work shaft support cylinder 20 Lower work clamp 27 Upper work clamp 33 Grindstone for inner diameter machining

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Claims (8)

[Claims] 1. An inner peripheral grindstone comprising a plurality of steps of trapezoidal grinding grooves having abrasive grains such as diamond fixed on the inner peripheral surface of a donut-shaped main body. 2. The inner peripheral grinding wheel according to claim 1, wherein a flat grinding peripheral surface is formed on the inner peripheral surface together with the plurality of grinding grooves. 3. The inner peripheral grindstone according to claim 1, wherein types and / or sizes of abrasive grains are different in the plurality of grinding grooves. 4. A grindstone shaft support cylinder on which an inner grindstone having a grinding groove formed on an inner peripheral surface is provided, and the inner grindstone is fixed to an upper surface of the grindstone shaft support cylinder through the upright direction of the grindstone shaft support cylinder. Along with rotatably supporting the cylindrical grindstone shaft, a means for rotationally driving the grindstone shaft is installed, and within the grindstone shaft,
A work shaft support cylinder having a lower work clamp for sucking a work at its upper end is inserted in a loosely inserted state, and the grindstone shaft support tube and / or the work shaft support tube are vertically and horizontally inserted. Grinding device for circular work, which can be moved in any direction. 5. The grinding device for a circular work according to claim 4, wherein the inner peripheral grinding wheel is one according to any one of claims 1 to 3. 6. An upper work clamp according to claim 4, further comprising an upper work clamp positioned coaxially with said lower work clamp, pressing said work from above and rotating integrally with said lower work clamp. An apparatus for grinding a circular work as described above. 7. An inner diameter machining grindstone which is supported by an inner diameter machining grindstone shaft support cylinder which is movable in a vertical direction and a horizontal direction and advances inside the upper and lower work clamps. 7. A grinding device for a circular work according to claim 5, wherein 8. The apparatus according to claim 4, further comprising means for rotating said work shaft support cylinder in a direction opposite to a rotation direction of said grinding wheel shaft.
8. A grinding device for a circular work according to 6 or 7.